Apparatus for heating asphalt surfaces.



No. 743,020. PATBNTED Novjs, 190,3.

J. W. NBSMITH.

APPARATUS FOR HEATING ASPHALT SURPACES.

APPLICATION FILED DBO. 27, 1902.. N0 MODEL. a 'SHEETS-SHEET 1.

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PATBNTED Nov. $1903.l

J. W. NESMITH. APPARATUS POR HEATING ASPHALT SURFAGES.

APPLICATION FILED DBG. 27, 1992.

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NO MODEL.

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PATENII-J) NOV! 3, 1903.

VJ. W. NESMITH. APPARATUS PoR HEATING ASPHALT SURFAGES.

PPIAIOATION FILED DEG. 27, 1902.

WHA/55555 v ,WM ATTORNEYS.

UNITED 'STATES atented November 3, IQOL 4PAnzNT OFFICE.

.iOnN vv. NEsivirrI-I, or DENvER, COLORADO, ASSIeNoR To ECONOMIC' ASPHALT STREET REPAIRS COMPANY, OE DENVER, COLORADO.

APPARATUS FOR HEATING ASPHALT SURFACES.

SPECIFICATION forming part of Letters Patent No. 743,020, dated November 3, 190g.

l Application filed December 27,1902. Serial No. 136,836. (No model.)

To all whom it may concern.-

Be it known that I, JOHN W. NESMITH, a citizen of the UnitedStates, residing at Denver, Colorado, have invented certain new and useful Improvements in Apparatus for Heating AsphaltSurfaces, of which the following is a specification.

My invention is an apparatus designed to be used` in the resurfacing or repair of asphalt pavements. `As is Well known, it is the practice to first soften the surface by applying heat thereto and then to cutout or remove the softened portion, adding fresh asphalt and treating this by rolling in the usual manner. I have ascertained by practical tests that better results can be secured by applying heated gaseous products of combustion and air to the surface to be treated, and thus protecting the Surface from the direct action of the iiame.

In carrying out my invention` I have utilized the method disclosed in LettersPatent of the United States granted to me March 3, 1896, No. 555,731, and Patent No. 575,974, of January 26, 1897. In these patents I disclose effective means for heatinga blast of air, the air being passed through a chamber from a blower or like supply and being heated economically and eifectually while passing through the chamber to the point of use, the heating means employed being a Suitable burner or burners supplied with oil or gasV under a pressure greater than that of the blast to be heated.

My present invention is an economical and practical adaptation of the method referred to to an apparatus for the 4repair or resurfacing of asphalt pavements'or, indeed, for use in any other situation requiring a highlyheated current or fioW of gases discharging upon the surface to be treated.

My invention also includes means for modifying or regulating the temperature of the blast.

The apparatus disclosed includes many novel features of construction, as will be hereinafter more fully described.

In the drawings, Figure l shows one form of the apparatus mounted on the frame of a steam-roller with the heating-chamber' in Section. Fig. 2 is an elevation of the apparatus shown in Fig. l. Fig. 3 is a sectional view of aA modified form of heating-chamber with parts in elevation. Fig. 4 is an end elevation, partly in section, of Fig. 3. Fig. 5 is a section on line of Fig. 3. Fig. 6 is aseotion on` line y y of Fig'. 3. Fig. 7 is a plan, and Fig. 8 is an elevation, ofauother form of the apparatus.

Referring to Figs. l and 2,1 find it convenient to Amount the apparatus on the frame of a steam-roller or other suitable vehicle driven by power other than animal power, as ready approach is thus permitted to the place requiring repair Without liability of tracking in the recently-repaired patches, though I may mount the apparatus in any suitable manner. A combustion-chamber is shown at A and is either water-jacketed or lined with asbestos. A blowerB is mounted upon the chamber, and the blast is directed through the pipe C to a cross pipe or head D, supported on the end of the combustion-chamber, and from this head a series of air-delivery pipes a extend into the interior of the combustion chamber for preferably more than half the length of the chamber. These delivery-pipes may be provided in number as may be" found suitable. I have shown sin, but this number may beincreased or diminished. The position of the burneris shown at E, and this maybe aburner adapted for oil, gas, or pulverized fuel, and is projected intol the chamber A by any suitable means, such as air or steam under pressure. It is necessary, of course, as described in my former patents, in order to maintain' a llame in the chamber that the pressure back of the fuel shall be greater than the air-blast from the blower B. The` freshair supply through the air-pipes a is thoroughly heated in its passage,and this promotes the combustion of the fuel at the burner and throughout the combustionchamber, and the gaseous products of combustionl and air pass out through openings?) inthe front Wall of the combustion-chamber, these openings being preferably four in number, as shown in Fig. 2, though the number may be increased or diminished. A hood F, of any suitable form, is adj ustably supported by chains c from projections d, mounted upon a shaft c, which is controlled byalever f, and thus the hood may bereadilyraised orlowered. Thehoodisofany shape, either, as shown, with a tapering top and side walls extending beyond the side lines of the apparatus at its extreme outer end, but tapering inwardly to meet the side Walls of the heating-chamber, or else of the form shown in Fig. 8, with the current of heated gases from the combustion-chamber entering it at the top, as more particularly hereinafter set forth. The hood may be provided with partition-walls c, and thus an independent heating-space is formed for one or more of the openings from the heating-chamber. The hood may thus be used simultaneously from side to side by opening all the gates h controlling the exit-openings from the combustion-chamber, or where it is desired to operate on patches or small spots the heat may be confined to one or more of the spaces and the gates of the other outlets kept closed. The

gates are readily controlled by chains e', one vfor each gate, running over sheaves k, this being representative of any other method of operating the gates. My experience has shown that this method of heatingis so effective that the heat requires to be modified or -else the asphalt street-surface will be destroyed by the intensity of the heat.

I provide for this in one way by means of a valve k', located in a box l, intermediate the ends of the blower-pipe, with an opening controlled by this valve, as at n, leading into the top of the combustion-chamber. This valve serves as a delector and by proper adjustment may deiiect any desired proportion of cold air directly into the combustion chamber, thus modifying the temperature of the gases being discharged.

In Figs. 3 to 6 l have shown a modiiied construction. In this form the combustion-chamber A is shown as cylindrical with a suitable lining. The pipe for the blast is shown at C/ discharging into ahead D', and from this head two pipes E E comm unicate with a casing F', forming an intermediate chamber between the pipes E' and the combustion-chamber. A series of pipes GQ preferably four in number, though they may be more or less, form a constant means of communication between the chamber F and the interior of the chamber A', these pipes being preferably of varying lengths, so as to distribute the heated combustion-air thoroughly, the burner being shown at E. In order to modify the heat when this is found necessary or desirable, a valve H is opened to a greater or less degree through the medium of a handle b, with the result that a supply of cold air is admitted directly to the chalnber A', thus modifying the heat of the outgoing blast of heatedv gases as it passes to the point of use`through the exit-pipe Gr.v

I do not limit myself to the details of construction, as it will be obvious that these may be materially changed without departing from the spirit of my inventiomthe essence of which resides in utilizing the gaseous products of combustion to soften or heat the surface to be treated without the direct action of the flame, and, secondly, in modifying or tempering the intensity of the heat by the admission of a current of cold air. In this way the temperature is regulated and controlled so that it shall be above the melting-point but below the burning-point of the asphalt material exposed to it.

Referring to Fig. 2, I may, as shown in dotted lines, subdivide the longitudinal compartments in the hood by dampers A2, so as to confine the heat when desired to smaller areas.V I may use one or more of these dampers in each division of the hood. I may also provide openin gs b2 in the side and end walls of the hood, closed by shutters c2, so as to induce a current by allowing passage of the heatedA gases, and thus more eifectually heat the surface at that particular point. I may in case the heating-chamber is provided with a water-jacket utilize it for pumping the feedwater of the boiler through it. The jacket may also serve the purpose of an ordinary boiler for the production of steam sufficient to operate the burner and blower.

In Figs. 7 and 8 I have shown another and most convenient form of construction and arrangement of the whole apparatus, operating in many of its variousparts essentially as described above, but more conveniently arranged for service on the street. In this form of construction the machinery and appliances are mounted on a frame conveniently made of channeled steel. A double-reversible vertical engine Hhas its crank-shaft provided with a pinion working in a gear on two counter-shafts placed below the engine. These counter-shafts are supplied with two sprocketpinions fm, connected by sprocket-chains with sprocket- Wheels p, attached to the drivingwheels, which carry most of the superincumbent load of the machine, and the machine is thus propelled on the street. A steeringwheel Ir is controlled by a hand-wheel t, operating-screw u, and nut c, which is pivoted to a controlling-army', said controlling-arm being keyed to the steering-head. A watertank Gr may be provided as an auxiliary to the boiler. This tank is placed in the upper part of the combustion-chamber A, thus utilizing heat from said chamber. The main parts of the heating device are similar to those shown in Figs. l and 2. In Figs. '7 and S the air-blast pipe from the blower is inclosed within the casing of the heating-chamber, and from the head D2 the pipes a3 extend horizontally to near the rear wall of the chamber, the burner being shown at E2. Engine B3 is utilized to actuate the blower. The outlet for the heated gases is through pipes 3 3, which project from thefront wall of the casing and have downward extensions 4. Valves h3 control the outiiow of the gaseous products. The hood F2 differs in construction, but not materially, from that in Figs. l and 2 in that it is dome-shaped and the gas- IOO IlO

ILM.4

. extensions 5l from the hood.

ecus products pass into it through the top through the pipes 4c, which telescope in like The hood is raised and lowered as in Figs. l and 2.

I claiml. In an asphalt-heater, a combustion-chamber, a blower or other source of air under pressure, one or more pipes between the blower and chalnber, means for discharging air directly into the current of heated gaseous products of combustion, and means for regulating the quantity of such discharge of air into the heated gases, substantially as described.

2. In an asphalt-heater,a combustion-chamber, a blower, a chamber intermediate the blower and combustion-chamber, distributing -pipes leadingtherefrom to the combustion-chamber, a Valved outlet from the combustion chamber and a distributing@ dome,

f substantially as described.

3. In an asphalt-heater,a combustion-chamber, means for introducing fuel therein un- 'in presence of two witnesses.

JOI-IN W. NESMITI-I. Witnesses:

A. C. I-IARTMAN, W. C. MACDONALD. 

